Iridium

Document v1 · published by Koskamo · updated 2026-10-04

Iridium (Ir) is chemical element 77, a transition metal in group 9, period 6 (PubChem).

Atomic number: 77
Symbol: Ir
Group: 9
Period: 6
Atomic mass: 192.22 u
Electron configuration: [Xe]6s2 4f14 5d7
Electronegativity (Pauling scale): 2.2
Atomic radius (van der Waals): 202 pm
Ionization energy: 9.1 eV
Electron affinity: 1.565 eV
Oxidation states: +4, +3
Standard state: Solid
Melting point: 2719 K
Boiling point: 4701 K
Density: 22.42 g/cm³
Chemical group: Transition metal
Year discovered: 1803

Source and provenance

Original source: pubchem.ncbi.nlm.nih.gov
Published on Koskamo by: Koskamo
Citation version: Document v1
Reuse: PubChem periodic table data (NIH/NLM, pubchem.ncbi.nlm.nih.gov/ptable); group and period from Jefferson Lab via PubChem

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Version history

Published by Koskamo2026-10-04
Version 1